Not applicable.
(1) Field of the Invention
The present invention relates to a hydraulic activated spreader arm aperture generation system for generating a volumetric aperture for multiple line towed arrays.
(2) Description of the Prior Art
Present mobile sonar arrays include two and three dimensional hull mounted arrays and towed linear arrays. Many of the towed linear arrays have multiple lines. Such array systems are shown in U.S. Pat. No. 4,958,331 to Wardle, U.S. Pat. No. 4,970,696 to Crews et al., and U.S. Pat. No. 5,841,733 to Bouyoucos et al.
The problem in the design of multiple line towed arrays is to provide a means for reliably generating and maintaining separation of the lines in a specified three-dimensional configuration. Any system for aperture generation must be compatible with the method of deploying and retrieving the towed system. For current technology, this means that the aperture generation system has to collapse to a significantly reduced volume prior to retrieval.
Also, the aperture generation system must operate under the following constraints: (1) maintain separation distances across relevant operating speed ranges; (2) allow deployment and retrieval of the towed system and proper operation of the sensors; (3) survive flank speed of tow platform; (4) operate reliably in a seawater environment; (5) meet temperature range compliance and hydrostatic pressure compliance; (6) meet material compatibility; and (7) maintain performance for a minimum of three months without maintenance in a submarine environment.
Accordingly, it is an object of the present invention to provide a spreader arm aperture generation system which is compatible with current towed arrays.
It is a further object of the present invention to provide a spreader arm aperture generation system as above which is simple in design and less expensive to produce.
It is yet another object of the present invention to provide a spreader arm aperture generation system as above which has a negligible impact on array performance and/or self noise.
It is still another object of the present invention to provide a spreader arm aperture generation system as above which has increased compatibility with a marine environment.
Still further, it is an object of the present invention to provide a spreader arm aperture generation system as above which produces an aperture independent of the tow speed of a platform.
The foregoing objects are attained by the hydraulic activated spreader arm aperture generation system of the present invention.
In accordance with the present invention, a spreader arm aperture generation system for use with a towed array is provided. The spreader arm aperture generation system broadly comprises a plurality of tow lines, a sleeve affixed to each tow line and joinable with lines of the towed array, and hydraulically activated means positioned between at least two of the sleeves for generating horizontal and vertical separation among the lines. The hydraulically activated means in a preferred embodiment of the present invention are formed by a plurality of inflatable tubes, which tubes extend between sleeves affixed to the lines.
Other details of the hydraulic activated spreader arm aperture generation system of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.